Totara LMS v19.1.5 and before is vulnerable to Incorrect Access Control. The login page code can be manipulated to reveal the login form. An attacker can chain that with missing rate-limit on the login form to launch a brute force attack.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1